package com.fh.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 
 * @包名 :com.fh.util
 * @文件名 :RelativeDateFormat.java
 *      TODO 类作用：java几秒前，几分钟前，几小时前，几天前，几月前，几年前的实现
 * @Author: 孙超文 386480250@qq.com
 * @Date: 2016-1-21 上午7:59:18
 */
public class RelativeDateFormat {
	private static final long ONE_MINUTE = 60000L;
	private static final long ONE_HOUR = 3600000L;
	private static final long ONE_DAY = 86400000L;
	private static final long ONE_WEEK = 604800000L;

	private static final String ONE_SECOND_AGO = "刚发布";
	private static final String ONE_MINUTE_AGO = "分钟前";
	private static final String ONE_HOUR_AGO = "小时前";
	private static final String ONE_DAY_AGO = "天前";
	private static final String ONE_MONTH_AGO = "月前";
	private static final String ONE_YEAR_AGO = "年前";

	public static void main(String[] args) throws ParseException {
		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:m:s");
		Date date = format.parse("2016-1-21 7:52:35");
		System.out.println(format(date));
	}

	public static String format(Date date) {
		long delta = new Date().getTime() - date.getTime();
		if (delta < (1L * ONE_MINUTE)) {
			long seconds = toSeconds(delta);
			return (seconds <= 0 ? 1 : "") + ONE_SECOND_AGO;

		}
		if (delta < (45L * ONE_MINUTE)) {
			long minutes = toMinutes(delta);
			return (minutes <= 0 ? 1 : minutes) + ONE_MINUTE_AGO;
		}
		if (delta < (24L * ONE_HOUR)) {
			long hours = toHours(delta);
			return (hours <= 0 ? 1 : hours) + ONE_HOUR_AGO;
		}
		if (delta < (48L * ONE_HOUR)) {
			return "昨天";
		}
		if (delta < (30L * ONE_DAY)) {
			long days = toDays(delta);
			return (days <= 0 ? 1 : days) + ONE_DAY_AGO;
		}
		if (delta < (12L * 4L * ONE_WEEK)) {
			long months = toMonths(delta);
			return (months <= 0 ? 1 : months) + ONE_MONTH_AGO;
		} else {
			long years = toYears(delta);
			return (years <= 0 ? 1 : years) + ONE_YEAR_AGO;
		}
	}

	private static long toSeconds(long date) {
		return date / 1000L;
	}

	private static long toMinutes(long date) {
		return toSeconds(date) / 60L;
	}

	private static long toHours(long date) {
		return toMinutes(date) / 60L;
	}

	private static long toDays(long date) {
		return toHours(date) / 24L;
	}

	private static long toMonths(long date) {
		return toDays(date) / 30L;
	}

	private static long toYears(long date) {
		return toMonths(date) / 365L;
	}
}
